A scraper-type tool for repairing strips in 3D printed architecture

Abstract

This utility model relates to a scraper-type tool for repairing strips in 3D printed building materials. It is used when the printing material is freshly extruded and in a malleable state. The tool includes a scraper section and a handle section. The front end of the scraper section has multiple crescent-shaped grooves with the same radius of curvature, which can conform to the contour of the printed strip. The working surface of each crescent-shaped groove has an inclination angle α. The handle section is detachably connected to the scraper section and is arranged with a lower front and higher rear to ensure that the scraping direction is parallel to the direction of manual horizontal advancement. The technical features of this utility model work together synergistically to provide a professional tool that can efficiently, accurately, and reliably solve the problem of repairing defects in strips printed on-site in 3D building construction. This significantly improves the quality of printed components, construction efficiency, and project reliability, effectively overcoming the bottleneck of manual repair.

Description

Technical Field

[0001] This utility model relates to the technical field of building 3D printing equipment and auxiliary tools, and more specifically to a scraper-type tool for repairing strips in building 3D printing. Background Technology

[0002] As an emerging construction method, 3D printing in architecture is gradually moving from the experimental verification stage to the practical engineering application stage. 3D printing technology rapidly forms building components by stacking mortar-like materials layer by layer, and the quality of this layer stacking directly affects the structural strength and geometric accuracy. However, 3D printing in architecture is usually carried out under non-constant, semi-outdoor, or on-site construction conditions, which involve various uncontrollable or semi-controllable interference factors. For example, the material itself carries the risk of segregation; thixotropic properties are significantly affected by ambient temperature and humidity; the mechanical system accumulates errors and positioning deviations during long-term operation; and if the nozzle trajectory is affected by uneven ground or structural vibrations, it can easily cause local path deviations or abnormal deposition.

[0003] In complex construction environments, printed strips are prone to defects in localized areas, such as strip bulging, edge lifting, upper layer compression and sinking, uneven boundaries, excessive build-up, path breakage, and deviation from the original trajectory. These defects not only affect the appearance quality but, more importantly, the adhesion of subsequent layers and the uniformity of the overall structure. In severe cases, they can even lead to component instability, failure to pass precision acceptance, and ultimately result in rework or abandonment, wasting materials and construction time.

[0004] To address sudden strip defects, most construction teams currently rely on on-site manual repairs using ordinary scrapers or plastering tools. However, these tools are typically flat, presenting the following limitations in their use:

[0005] Tool geometry mismatch problem: The planar structure of the commonly used flat scraper or plastering tool on site does not fit the curved section of the strip, resulting in misalignment of the cross-sectional contour and discontinuous bonding between layers after repair.

[0006] Operating angle conflict issue: When manually repairing, the tool needs to be pushed horizontally, but the angle between the working surface of the traditional tool and the printed layer is unreasonable, which can easily scratch the cured lower layer or cause uneven repair.

[0007] Therefore, how to provide a scraper-type tool for repairing strips in 3D printed architecture is a problem that urgently needs to be solved by those skilled in the art. Utility Model Content

[0008] Therefore, the purpose of this utility model is to propose a scraper-type tool for repairing strips in 3D printed architecture, thereby solving the problems mentioned in the background art.

[0009] The technical solution of this utility model is a scraper-type tool for repairing 3D printed strips in architecture, used when the printing material has just been extruded and is in a malleable state, including:

[0010] The scraper section has multiple crescent-shaped grooves with the same radius of curvature at its front end, which can conform to the contour of the printing strip; and the working surface of the crescent-shaped grooves has an inclination angle α.

[0011] The handle is detachably connected to the scraper, and the handle is arranged with the front lower and the back higher to ensure that the scraping direction is parallel to the manual horizontal pushing direction.

[0012] According to the scraper-type tool of this utility model, the crescent-shaped groove has 3-7.

[0013] According to the scraper-type tool of this utility model, the tilt angle α makes the working surface of the crescent-shaped groove form an angle of 10°-30° with the vertical plane of the printing strip.

[0014] According to the scraper-type tool of this utility model, the radius of curvature of the crescent-shaped groove 11 is selected from 20mm, 30mm, 40mm, 50mm, and 60mm, depending on the width of the printing strip.

[0015] According to the scraper-type tool of this utility model, the handle is one of a straight handle, a curved handle, a closed ring handle, or an industrial standard interface handle, which can be adapted to manual hand-held or industrial robotic arm gripper operation.

[0016] According to the scraper-type tool of this utility model, the handle part and the scraper part are connected by any one of the following methods: pin, snap, or thread.

[0017] According to the present invention, the scraper-type tool is made of high manganese steel or reinforced nylon, and its working surface is provided with an anti-adhesion coating.

[0018] According to the scraper-type tool of this utility model, the handle includes an ABS rigid support area and a TPR flexible anti-slip area.

[0019] As can be seen from the above technical solution, compared with the prior art, the present invention has the following technical effects:

[0020] 1. By designing a crescent-shaped groove with a specific radius of curvature, the key problem of geometric mismatch between traditional flat tools and the curved cross-section of the printed strip is solved. This allows the scraper's working surface to precisely conform to the strip's contour, ensuring accurate cross-sectional shape and continuous interlayer adhesion after repair, and preventing contour misalignment. Simultaneously, the groove's working surface has an inclination angle α, and combined with the handle's front-low, rear-high arrangement, the operating angle is optimized. This ensures that the manual horizontal advance direction is naturally parallel to the scraping direction, effectively avoiding the risk of scratching the underlying cured material and applying a more uniform scraping force, significantly improving repair uniformity and ease of operation. It is limited to use when the printed material is freshly extruded and in a malleable state, ensuring optimal timing and effectiveness for the repair operation.

[0021] 2. Limiting the number of crescent-shaped grooves to 3-7 provides an optimal balance between coverage and operational flexibility. Too few (<3) may result in insufficient coverage area for a single repair, leading to low efficiency; too many (>7) will make the tool too large and cumbersome, making it difficult to precisely control local repairs, especially in narrow or complex areas. This range design ensures that the tool can efficiently repair defects within a certain length range while maintaining good operational precision, adapting to common defect distributions on-site.

[0022] 3. The tilt angle α, which forms a 10°-30° angle between the working surface of the crescent-shaped groove and the vertical plane of the printing strip, is the key angle range for the tool to achieve optimal performance. An angle that is too small (<10°) may result in the working surface and strip contact being too "flat," similar to a traditional flat scraper, still posing a risk of scratching the underlying layer and uneven repair. An angle that is too large (>30°) may cause the scraping force to be directed too downwards, compressing rather than flattening the material, easily causing strip deformation or material accumulation, and requiring more effort to operate. This preferred angle range ensures that the scraping force can effectively act on the material layer to be repaired, smoothly guides the flow of excess material, maximizes the protection of the underlying structure, and achieves a smooth transition repair effect.

[0023] 4. The curvature radius of the crescent-shaped groove can be selected from 20mm, 30mm, 40mm, 50mm, and 60mm, significantly improving the tool's versatility and adaptability. In architectural 3D printing, the strip width (i.e., cross-sectional curvature) used in different projects or different parts of the same project may vary. Providing standardized options for multiple curvature radii allows users to quickly match and replace the scraper head according to the actual size of the printed strip, ensuring that the groove always precisely conforms to the target strip contour, fundamentally solving the "geometric mismatch" problem and achieving high-quality repair.

[0024] 5. The handle can be straight, curved, closed-ring, or with an industrial standard interface, greatly expanding the tool's applicable scenarios and operating modes. Different handle designs adapt to different ergonomic needs (such as reducing fatigue and facilitating force application) and different operating subjects (manual hand-held or robotic arm gripping). In particular, the "industrial standard interface handle" design allows the tool to be seamlessly integrated into automated repair systems or robotic arms, meeting the needs of future intelligent and automated construction, and improving repair efficiency and operational safety (especially in hazardous or high-intensity environments).

[0025] 6. The handle and scraper are connected by detachable methods such as pins, snaps, and threads, providing a convenient modular design. This design facilitates: quick replacement of scraper sections with different radii of curvature; replacement or adaptation of different types of handles; and independent maintenance or replacement of easily damaged scraper sections without discarding the entire tool. This reduces maintenance costs and improves tool flexibility and lifespan.

[0026] 7. The scraper section is made of high-manganese steel or reinforced nylon with an anti-adhesion coating, comprehensively improving the tool's durability, functionality, and repair quality stability. High-manganese steel offers excellent wear resistance and rigidity, suitable for high-intensity, long-term use. Reinforced nylon has good toughness, is lightweight, and offers some wear resistance, and may be less expensive, making it suitable for weight-sensitive or specific chemical environments. The anti-adhesion coating effectively reduces the adhesion and residue of slurry-like printing materials on the scraper's working surface, ensuring smooth and continuous scraping action, preventing secondary damage or unevenness to the repair surface due to material adhesion, ensuring consistently high-quality repair results, and reducing cleaning needs.

[0027] 8. The handle is manufactured using a dual-material injection molding process, comprising a rigid ABS support area and a flexible TPR anti-slip area. The rigid ABS area ensures the structural strength of the handle and the reliable connection to the scraper / robotic arm interface. The flexible TPR anti-slip area provides a comfortable grip, effectively absorbs vibration, and offers excellent anti-slip performance in wet or oily work environments, reducing operator fatigue and preventing accidental tool slippage that could lead to accidents or damage to printed parts.

[0028] In summary, the scraper-type tool provided by this utility model achieves the following core objectives through the synergistic effect of multiple technical features, including precise geometric matching of the crescent-shaped groove and the strip contour, optimized scraping angle design, an adaptable handle that meets ergonomic / automation requirements, and material selection that balances durability and functionality:

[0029] Completely eliminates geometric mismatch: thoroughly solves the problem of misfit between traditional planar tools and curved strips, ensuring accurate cross-sectional shape and continuous, seamless interlayer bonding after repair.

[0030] Eliminating operational conflicts: By using an angle α on the working surface, which creates a 10°-30° angle between the crescent-shaped groove working surface and the vertical plane of the printing strip, combined with the handle angle design, the horizontal propulsion force is naturally converted into an ideal scraping force. This clear spatial angle definition effectively protects the underlying cured structure, enabling uniform and controllable repair operations, significantly reducing operational difficulty and the risk of errors. It is the quantitative key to solving the "operation angle conflict" problem.

[0031] Improve repair quality and efficiency: Perform precise and rapid repairs during the material's optimal plasticity period to effectively eliminate defects such as bulges, curling edges, and unevenness, ensuring the bonding quality of subsequent printed layers and the uniformity and stability of the overall structure, and reducing rework and scrap.

[0032] Enhanced adaptability and versatility: Modular design (interchangeable scraper head, multiple handles), multiple curvature options, and support for human-machine / machine-machine dual-mode operation enable the tool to flexibly adapt to different strip sizes, different operating environments (manual / automated), and different operator needs.

[0033] Ensuring long-term reliability and cost-effectiveness: Wear-resistant / non-stick materials and coatings extend tool life, modular design reduces maintenance and replacement costs, and dual-material handles improve operating safety and comfort. Attached Figure Description

[0034] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on the provided drawings without creative effort.

[0035] Figure 1 A schematic diagram of a scraper-type tool for repairing 3D printed strips in architecture, provided by this utility model;

[0036] Figure 2 A three-dimensional view showing the longitudinal section of the scraper section is provided;

[0037] Figure 3 for Figure 2 Side view;

[0038] Figure 4 The diagram illustrates an application example of this utility model. Detailed Implementation

[0039] The embodiments of this utility model are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain this utility model, and should not be construed as limiting this utility model.

[0040] In the description of this utility model, it should be understood that the terms "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model.

[0041] Currently, most construction teams rely on on-site manual labor using ordinary scrapers or plastering tools for emergency repairs. However, these tools are usually planar in structure and do not match the geometry of the printed strip outline, making it difficult to ensure a continuous and consistent outline after repair. In addition, operators often perform rapid operations on-site by pushing the tool horizontally. If the contact angle between the tool and the printed strip is not reasonable, it can easily cause uneven scraping, damage to the printed part, or low repair efficiency.

[0042] Therefore, this utility model provides a scraper-type tool for repairing 3D printed strips in construction, specifically designed for repairing materials immediately after extrusion while they are still in a malleable state. See appendix. Figure 1 The tool includes a scraper part 1 and a handle part 2. The front end of the scraper part 1 is provided with multiple crescent-shaped grooves 11 for conforming to the outline of the printing strip. The handle part is detachably connected to the scraper part 1 and is arranged at an angle with the front lower and the back higher.

[0043] The crescent-shaped grooves 11 on the scraper part 1 are preferably 3-7 in number (e.g., Figure 1 and 2 As shown in the diagram, a strip length of 10–30 cm is covered in a single operation, balancing repair efficiency and local precision control. All grooves have the same radius of curvature and are selected from 20mm, 30mm, 40mm, 50mm, and 60mm according to the target strip width (e.g., a 40mm radius adapts to a standard 40mm wide strip), ensuring that the groove surface and the strip's arc cross-section fit perfectly, thus solving the geometric mismatch problem.

[0044] The tilt angle α makes the working surface of the crescent-shaped groove 11 form an angle of 10°-30° with the vertical plane of the printing strip (e.g., Figure 3(As shown in the cross-sectional view), this angle makes the scraping force direction consistent with the material flow direction: Working principle: When the tool is pushed horizontally, the tilt angle α decomposes the force into a horizontal scraping component (repairing the surface layer) and a vertical protection component (avoiding damage to the lower layer), completely eliminating the conflict of operating angles.

[0045] When α = 15°, it is suitable for low-temperature, high-viscosity mortars with low scraping resistance; when α = 25°, it is suitable for high-temperature, low-viscosity materials to prevent material splashing.

[0046] The handle 2 is designed for adaptability, with an angle configuration of 15°–20° with respect to the horizontal plane (lower in the front and higher in the back), so that the direction of manual horizontal pushing force is naturally parallel to the scraping direction of the scraper working surface, reducing operator fatigue.

[0047] The scraper section 1 and the handle section 2 can be quickly disassembled and assembled via pins, clips, or threads, making it easy to replace scraper sections with different radii of curvature.

[0048] The multi-mode handle offers options for manual operation: straight handle (lightweight), curved handle (effort-saving lever), and closed ring handle (anti-drop); for robotic arm operation, an industrial standard interface handle (such as ISO9409 interface) can be selected, supporting integration with automated repair systems.

[0049] Key materials and processes in this utility model: The substrate of the scraper part 1 can be high manganese steel (hardness HRC55-60) or glass fiber reinforced nylon (flexural strength >150MPa), which respectively meet the requirements of high strength and wear resistance and lightweight.

[0050] The scraper section is recommended to be made of 304 high manganese steel plate with a thickness of 1.5–2.0mm. After the crescent shape is made by laser cutting, the scraping corner structure is formed by CNC bending equipment. Finally, the surface is sprayed with PTFE or ceramic anti-adhesion coating to improve cleanliness and corrosion resistance.

[0051] Alternatively, the main body of the scraper can be made of PA6+30%GF glass fiber reinforced nylon, and the scraper and handle can be connected separately. The mold design should consider the scraping angle and groove demolding requirements. For the handle, it is recommended to use a two-material injection molding process (ABS+TPR) to achieve a combination of rigid support and flexible grip area, improving operating comfort and fatigue resistance.

[0052] The working surface can be sprayed with a polytetrafluoroethylene (PTFE) anti-adhesion coating with a thickness of 50–100 μm, which significantly reduces mortar adhesion and ensures continuous and smooth scraping.

[0053] Handle Part 2: Adopts a dual-material injection molding process: the inner layer is ABS engineering plastic (providing rigid support), and the outer layer is covered with TPR soft rubber (Shore hardness A60-70), forming an anti-slip texture and shock-absorbing layer, suitable for wet construction sites.

[0054] In this utility model, unless otherwise explicitly specified and limited, the terms "installation," "connection," "joining," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. For those skilled in the art, the specific meaning of the above terms in this utility model can be understood according to the specific circumstances.

[0055] See appendix Figure 4 Example of the operation process of this utility model:

[0056] Before use, check that the scraper is clean to avoid hard particles such as sand adhering to the print strip and causing scratches or excessive adhesion.

[0057] Repair should be performed within 2–5 minutes after the printed strip is extruded (during the material's plasticity period); Tool configuration: Select a scraper with a curvature radius corresponding to the strip width (e.g., 40mm), and equip it with a bent handle;

[0058] Repair procedure: Hold the handle and advance horizontally along the direction of the printing strip (both in the direction of thrust and scraping). When using the tool, keep it parallel to the printing path to avoid dragging it in the opposite direction, which could cause breaks or disturb the structural layers.

[0059] The crescent-shaped groove 11 conforms to the outline of the printing strip, with an inclination angle α = 20° guiding excess mortar to flow evenly to both sides. A single repair can cover more than 3 groove areas (approximately 15cm in length), eliminating bulges and edge lifting defects. After use, rinse with clean water and dry promptly to prevent mortar residue from hardening and affecting the accuracy of the next use. For long-term use, it is recommended to regularly check the wear of the groove openings and replace the scraper components if necessary to ensure repair effectiveness.

[0060] The optional solutions in this utility model include: Optimizing the tilt angle α: For repairing ultra-thick strips, α = 10° is used to increase the scraping depth; for repairing thin layers, α = 30° is used to reduce the downward pressure.

[0061] In addition, the robotic arm collaboration solution clamps an industrial interface handle onto a six-axis robotic arm, enabling unmanned repair through a preset trajectory. The clear definition of the tilt angle α (relative to the vertical plane) ensures accurate angle calculation for the automated program.

[0062] The technical features of this utility model work together synergistically to provide a professional tool that can efficiently, accurately, and reliably solve the problem of repairing strip defects on-site in 3D printing of buildings. This significantly improves the quality of printed components, construction efficiency, and engineering reliability, and effectively overcomes the bottleneck of manual repair described in the background art.

[0063] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. In addition, those skilled in the art can combine and integrate the different embodiments or examples described in this specification.

[0064] Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of the present invention.

Claims

1. A scraper-type tool for repairing 3D printed strips in construction, characterized in that, Printing materials are used immediately after extrusion and while still in a malleable state, including: The scraper part (1) has multiple crescent-shaped grooves (11) with the same radius of curvature at its front end, which can fit the outline of the printing strip; and the working surface of the crescent-shaped groove (11) has an inclination angle α. The handle (2) is detachably connected to the scraper (1). The handle (2) is arranged in a way that is lower in the front and higher in the back to ensure that the scraping direction is parallel to the manual horizontal pushing direction.

2. A scraper-type tool for repairing 3D printed strips in architecture according to claim 1, characterized in that, The crescent-shaped groove (11) has 3-7.

3. A scraper-type tool for repairing 3D printed strips in architecture according to claim 1, characterized in that, The tilt angle α makes the working surface of the crescent-shaped groove (11) form an angle of 10°-30° with the vertical plane of the printing strip.

4. A scraper-type tool for repairing 3D printed strips in architecture according to claim 1, characterized in that, The radius of curvature of the crescent-shaped groove (11) is selected from 20mm, 30mm, 40mm, 50mm, and 60mm, depending on the width of the printed strip.

5. A scraper-type tool for repairing 3D printed strips in architecture according to claim 1, characterized in that, The handle (2) is one of a straight handle, a curved handle, a closed ring handle, or an ISO9409 interface handle, which can be adapted to manual hand-held or industrial robotic arm gripper operation.

6. A scraper-type tool for repairing 3D printed strips in architecture according to claim 1, characterized in that, The handle (2) and the scraper (1) are connected by any one of the following methods: pin, snap, or thread.

7. A scraper-type tool for repairing 3D printed strips in architecture according to any one of claims 1-6, characterized in that, The scraper part (1) is made of high manganese steel or reinforced nylon, and its working surface is provided with an anti-adhesion coating.

8. A scraper-type tool for repairing 3D printed strips in architecture according to any one of claims 1-6, characterized in that, The handle portion includes an ABS rigid support area and a TPR flexible anti-slip area.

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